1. Field of the Invention
The present invention relates to apparatus for counting, stacking and squaring bundles of flat articles, and more particularly, to apparatus for counting, stacking and squaring folded corrugated paperboard boxes.
2. Description of the Prior Art
Bundle formers for paperboard boxes are often referred to in the art as understackers because as the boxes leave the folder portion of the flexo-folder-gluer they enter the bundle former beneath the preceding box and form the stack from the bottom. These apparatus have been used for years in the box industry to form square stacks of folded boxes. However, in the prior art bundle formers have necessarily been complicated in that they included numerous gears, chains and sprockets and the lubricating and maintenance problems asociated with them. Also, in the prior designs the timing of the drive belt, lifting mechanism and squaring plate of the bundle former must be coordinated with the flexo-folder-gluer. Loss of coordination can cause jams of box blanks which require that the flexo-folder-gluer and stacker to be shut down with the attendant losses resulting from the down time.
The present invention overcomes the foregoing problems of the prior art by providing a bundle former having a simple and reliable drive mechanism. Further, the timing of the drive belt, lifting mechanism and squaring plate does not have to be sequenced with the timing of the flexo-folder-gluer.